The present invention relates to unsubstituted, monosubstituted and disubstituted 5,5'-bis-1,2,4-triazinyl compounds which possess valuable herbicidal activity, particularly as selective herbicides for agronomic crops such as corn, sorghum, soybeans, wheat, oats and the like. The instant invention further relates to active herbicidal compositions and to methods for controlling inhibiting or modifying the growth of vegetation.
Various 1,3,5-triazine compounds have been previously suggested for use in the control of undesired weeds (see, for example, Belgian Pat. No. 549,590). Moreover, various structurally unrelated bis-1,2,4-triazinyl compounds have been suggested as a potentially active class of fungicides and herbicides (see, for example, U.S. Pat. No. 3,498,981).
The preparation of certain substituted bis-1,2,4-triazinyl compounds are described in Krass et al. "1,2,4-triazines X: Dimerizations of 1,2,4-triazines" in J. Hetero. Chem., Vol. 10, 343 (1973) and Krass et al., "1,2,4-triazines XII: Synthesis of 5-carboxamido-1,2,4-triazines via an Addition-Oxidation Reaction", J. Hetero. Chem. Vol. 11, 43-44 (1974)). More specifically, these authors have described the preparation of 5,5'-bis-1,2,4-triazinyls by sodium methoxide or aqueous potassium cyanide catalyzed coupling of suitable triazine starting materials.
U.S. Pat. No. 3,498,981 to Culbertson, granted Mar. 3, 1970, describes various 5-monosubstituted-3,5-disubstituted-3,3'-bis- and 5,5'-bis- as-triazinyls and methods for the preparation thereof. The substituents at the 3,3' positions of the respective triazine rings include alkyl, carbocyclic aromatic, pyridyl, pyrimidyl, quinolyl and thiazolyl of 1 to 20 carbon atoms. The preferred exemplified compounds have substituted aromatic carbocyclic or nitrogen-containing heterocyclic substituents at the 3,3' positions as well as at the 5,5' positions. The patentee indicates that the compounds and compositions of the invention are useful as corrosion inhibitors for lubricating oils, coatings for metal substrates and to provide a sensitive test for the presence of ferrous ions and that bis-as-triazinyls containing ferroin moieties may be useful as fungicides or herbicides (although no specific test data with respect to herbicidal activity is presented).
U.S. Pat. No. 3,671,523, granted June 20, 1972, relates to various substituted 4-amino-1,2,4-triazine-5-one herbicidal agents outside the scope of the instant bis-1,2,4-triazinyls.